/*
     This file is part of GNUnet
     (C) 2006, 2009 Christian Grothoff (and other contributing authors)

     GNUnet is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published
     by the Free Software Foundation; either version 3, or (at your
     option) any later version.

     GNUnet is distributed in the hope that it will be useful, but
     WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with GNUnet; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.
*/

/**
 * @file datacache/plugin_datacache_template.c
 * @brief template for an implementation of a database backend for the datacache
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_datacache_plugin.h"


/**
 * Context for all functions in this plugin.
 */
struct Plugin
{
  /**
   * Our execution environment.
   */
  struct GNUNET_DATACACHE_PluginEnvironment *env;
};


/**
 * Store an item in the datastore.
 *
 * @param cls closure (our "struct Plugin")
 * @param key key to store data under
 * @param size number of bytes in data
 * @param data data to store
 * @param type type of the value
 * @param discard_time when to discard the value in any case
 * @param path_info_len number of entries in 'path_info'
 * @param path_info a path through the network
 * @return 0 if duplicate, -1 on error, number of bytes used otherwise
 */
static ssize_t
template_plugin_put (void *cls, const struct GNUNET_HashCode * key, size_t size,
                     const char *data, enum GNUNET_BLOCK_Type type,
                     struct GNUNET_TIME_Absolute discard_time,
		     unsigned int path_info_len,
		     const struct GNUNET_PeerIdentity *path_info)
{
  GNUNET_break (0);
  return -1;
}


/**
 * Iterate over the results for a particular key
 * in the datastore.
 *
 * @param cls closure (our "struct Plugin")
 * @param key
 * @param type entries of which type are relevant?
 * @param iter maybe NULL (to just count)
 * @param iter_cls closure for iter
 * @return the number of results found
 */
static unsigned int
template_plugin_get (void *cls, const struct GNUNET_HashCode * key,
                     enum GNUNET_BLOCK_Type type,
                     GNUNET_DATACACHE_Iterator iter, void *iter_cls)
{
  GNUNET_break (0);
  return 0;
}


/**
 * Delete the entry with the lowest expiration value
 * from the datacache right now.
 *
 * @param cls closure (our "struct Plugin")
 * @return GNUNET_OK on success, GNUNET_SYSERR on error
 */
static int
template_plugin_del (void *cls)
{
  GNUNET_break (0);
  return GNUNET_SYSERR;
}


/**
 * Entry point for the plugin.
 *
 * @param cls closure (the "struct GNUNET_DATACACHE_PluginEnvironmnet")
 * @return the plugin's closure (our "struct Plugin")
 */
void *
libgnunet_plugin_datacache_template_init (void *cls)
{
  struct GNUNET_DATACACHE_PluginEnvironment *env = cls;
  struct GNUNET_DATACACHE_PluginFunctions *api;
  struct Plugin *plugin;

  plugin = GNUNET_malloc (sizeof (struct Plugin));
  plugin->env = env;
  api = GNUNET_malloc (sizeof (struct GNUNET_DATACACHE_PluginFunctions));
  api->cls = plugin;
  api->get = &template_plugin_get;
  api->put = &template_plugin_put;
  api->del = &template_plugin_del;
  GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "template",
                   _("Template datacache running\n"));
  return api;
}


/**
 * Exit point from the plugin.
 *
 * @param cls closure (our "struct Plugin")
 * @return NULL
 */
void *
libgnunet_plugin_datacache_template_done (void *cls)
{
  struct GNUNET_DATACACHE_PluginFunctions *api = cls;
  struct Plugin *plugin = api->cls;

  GNUNET_free (plugin);
  GNUNET_free (api);
  return NULL;
}



/* end of plugin_datacache_template.c */